Minimally Invasive Intraoperative Multicatheter Breast Implant for Perioperative High-Dose-Rate Brachytherapy in Early Breast Cancer Treated With Conservative Surgery

Abstract

To assess the safety and feasibility of MIOMBI in breast conservative surgery of breast cancer. Multicatheter Interstitial Breast Brachytherapy (MIBB) is an effective and safe technique for Accelerated Partial Breast Irradiation (APBI) in properly selected breast cancer patients treated with conservative surgery. MIBB technique allows reach the highest dose conformity and sparing healthy tissue ability respect of different APBI methods (Balloon, 3DCRT and Intraoperative Radiotherapy). MIBB is usually performed as closed-cavity procedure. This condition allows proper selection patients for APBI according to definitive pathological features but has some disadvantages since implies a second operation room visit for patient, determine a indirect visualisation of tumor bed with the consequently risk to make a geographical error dimmed frequently by performing extensive implants. Minimally Invasive Intraoperative Multicatheter Breast Implant (MIOMBI) represents an alternative to classic MIBB procedure with potential logistics, clinical and cosmetics advantages. Patients with early breast cancer candidates for conservative surgery were eligible for MIOMBI technique with 6F flexible catheters. Perioperative high-dose-rate brachytherapy (PHDRBT) was delivered as APBI (3.4 Gy for 10 in five days) in patients who met low- and intermediate-risk criteria according to GEC ESTRO recommendations, (women older than 40 years, infiltrating ductal carcinoma less than 2 cm with extensive intraductal carcinoma less than 25%, pN0, free margins more than 2mm and intraductal carcinoma less than 3 cm.) Those patients who did not meet previous criteria receive PHDRBT as anticipatory boost (4 fractions of 3.4 Gy in two days BAT) followed by hypofractionated whole breast irradiation 39.9 Gy in 15 fractions. From April 2010 to July 2013 101 consecutive breast cancer patients have been treated with conservative surgery and MIOMBI. The median time for MIOMBI procedure was 25 minutes. The median of number of catheter employed was 9 (4-14). No intraoperative complications were observed. Major complications RTOG grade 3-4 (acute and late) was observed only in one patient (1%) who suffered bleeding complication after implant remove. Infection (mastitis or abscess) was observed in 3 patients (2%). Fat necrosis with no symptoms was observed in 2 patients. PHDRBT was delivered as APBI in 64 patients (60%) and as a boost in 34 (40%). The median of CTV-T (clips zone plus 2 cm) was 41 cc with a median D90 of 3.27 Gy (96%) and DHI in CTV-T of 0.71. The median V100 and V150 was 60cc and 13cc, respectively, with a median DHI of 0.76. Median D10 in high-risk skin zone was 1.91 Gy (56%). With a median followup of 22 months (2-34) no (local, elsewhere, regional or distant) failure was observed. Cosmetic outcomes were evaluated in 46 of 64 APBI treatments (71%) with excellent and good results in 61% and 37%, respectively, and fair in 2%. Minimally invasive intraoperative multicatheter breast implant (MIOMBI) for perioperative high-dose-rate brachytherapy (PHDRBT) avoids a second surgical procedure, allows direct visualisation of tumor bed reducing the implant extension and keeps all advantages (dosimetric and proper selection patients for APBI) of the classic MIBB technique.